<p><b>(A)</b> Chromatin interaction specificity analysis. The interaction specificity of a locus is estimated by defining an entropy value, which measures the interaction preference of genomic region with others. The larger the entropy value is, the less specific are its interactions with other genomic regions (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119672#pone.0119672.s001" target="_blank">S1 Text</a>). Loci in fission yeast show significantly larger entropy values and therefore form more random interactions than in budding yeast, in both Hi-C experiments and structure population (both p-value<1E-16). (<b>B</b>) The distribution of the distance ratio for lowly expressed genes and highly expressed genes. Lowly expressed genes are significantly dispersed than randomly selected loci (dashed vertical line), with a p-value<1E-16 and Cohen’s d is 0.72. The highly expressed genes are significantly clustered with a p-value<1E-16 and Cohen’s d is 0.33. (<b>C</b>) Combined gene localization probability density (LPD) plots for highly expressed genes and lowly expressed genes in the two yeasts.</p>